Process for producing a bleaching, sterilizing, or conditioning agent.



PATBNTED MAY 21, 1907.

v s. LEETHAM. PROCESS FOR PRODUCING A BLBAOHING, STBRILIZING, QR CONDITIONING AGENT.

APPLICATION FILED JULY16,1904.

I III-"ENE? I To all whom it may concern.-

N TED STATES PATENT OFFICE. I

SIDNEY LEETHAM, on rock, ENGLAND, ASSIGNOR TO THE- ozoNIzEn OXYGEN COMPANY LIMITED,'OF MANCHESTER, ENGLAND.

PROCESSFORPRODUCINGA BLEACHING, STERILIZING, R CONDITIONING AGENT.

Specification of Letters Patent.

. Patented May 21, 1907.

Application filed July s, 1904. Serial No. 216.892.

. Be it known thatI, SIDNEY LEETHAM, a subjectef-theKing of GreatBritain and Ireland, residing at Elm Bank, York, in the specification, for whichI have applied for a pose v I g to the other, for charging air with ozone, but

ditions.

county of York, England, miller, have invented a certain new and useful Process for Producing a Bleaching, sterilizing, or Conditioning Agent, ofwhich the following is a atent in Great Britain, filed March 9, 1904, 0. 5,790.

My invention relates to the production of an im roved gaseous agent, applicable for bleaching, conditioning or sterillzing flour or other materials requiring to be thus treated, or 'for sterilizing milk or food productsor other substances liable to fermentation or decay, or for bleaching cotton yarns, calico,

works with a sparkmg electrical discharge,

and the other witha silent electrical dischar e or inductive efiect; Frichot prothe one apparatus as an alternative I have found that the gaseous agent produced varies considerably in composition in the two forms of a paratus, and under different cont may vary'from the extreme at one end of aircharged almost solely with ozone, produced by the silent discharge or induction type of apparatus, .to the extreme at the other end of aircontaining'very little ozone but some other compound or compounds (probably a'mixture of nitric oxid,

nitro en-trioxid and nitrogen peroxid, but possi ly some other substance or. substances not yet identified), having bleaching or ster ilizing properties, produced by the sparking.

discharge type of apparatus. 7

I have found that-a greatly improved bleaching or conditioning or sterilizin agent is. obtained @by passing air throng both typesv of apparatus, either in succession or not, that is tosay, by my invention either I pass air successively throu han ozonizer and an apparatus in which t ere are sparkingdischarges, in any order, or I pass air through an ozonizer. and mix it with air which "has been passed through a sparking discharge apparatus. The treated air thus obtained constitutes my new agent which I bring into in- "timate contact in any suitable manner, with the material requiring to be bleached, sterilized or conditioned. The best efiect is ob tained when the air is passed first through an ozonizer and then throu h a sparking discharge apparatusj the el ect is not, so good when th s order of using the apparatus is reversed and is still less good when a current of air which has passed through the ozonizer is mixed with'one that has passed through the sparking discharge apparatus, although in both the last named cases the effect is an improvement as compared with the use of either I apparatus alone.

My new bleaching agent consists therefore of air laden with ozone and containing a proportion of the product of the action ofoa sparking electrical discharge on air, which is probably an oxid or oxidsof nitrogen, although the odor of the gas indicates the presence of some other substance or substances not yet identified. My invention is not limited to the nature of the apparatus employed so long as one of them is an ozonizer working by silent discharge. while the other has sparking dis-- charges- To illustrate my invention, however, I will describe with reference, to the accompgnying drawings,

en used.

Figure 1 is a front view of the apparatus necessary for generating the mixture of aseous products with which the mater-ia reguiring to be bleached or sterilized and confire-proof casing a which is shown in the an apparatus which has drawings as having had its doors removed.

Fig. 2 is a side view with the side of the easing a, removed. Fi ,3 is a horizontal section on line 3-3 of fig. 1.

, The apparatus comprises a dynamo b, a transformer c, an ozonizer d and a sparkingdi'scharge apparatus 2, all conveniently arranged in a fire-proof casing a in superimosed compartments therein as shown in igsf1and2.

The ozonizer (1 may be of the well known type consistingof alternating plates (1 and grids d of metal, with interposed sheets of proof plates 6, preferably slate slabs.

ozonizer and all the plates with the other. ,An air inlet f and outlet 9 are provided at opposite ends of the casing b so that airintroduced into the one must pass between the I plates and'grids on its Way to the-other.

The sparking, discharge apparatus may consist of a trunk orconduit built up of fireconduit is sup orted on suitable brackets is fixed to the casing h and through the top and bottom plates 41 are passed electrodes m of metal wire, carbon or other suitable material,each' of the upper ones being in the same axialline with a lower one and referably distant from it by about one-eighth of an inch. 7 At the part ofthe conduit where these electrodes are, the side may conveniently have a glass window in it to allow of the characterof the sparks between the electrodes being examined. As shown in Fig. 3 the outlet-from the ozonizer casing communicates with one end of this conduit so that the air having traversed the ozonizer passes between the electrodes to the outlet [at the other end of the conduit.

It is advantageous to supply both ozonizer and sparking apparatus from the same source of current and to connect the ozonizer in series with the sparking electrodes, that is to say one end of the secondary circuit of the transformer is connected to the lates of the ozonizer and the other end of t e circuit to the grids, the sparking electrodes being interposed in series in the circuit either on the late side or on thegrid side of the ozonizer. he ozonizer thus acts as a condenser in the sparking discharge circuit, with the advantage that the electric sparks are rendered more stable, because the conditions of the circuit are such as to produce a considerable fall of potential at the sparking electrodes as thecurrent. increases, this fall of potential beinggiven by the ozonizer so long as the "latter is in series with the sparking electrodes. Moreover, the apparatus becomes practically self regulating inasmuch as the current from the I ozonizer and that throu h thesparking; electrodes mustalways be t e same if thetwo arein series,, ,whereby the amount of ozone produced is ,increased as,

- the currentrises by .just about as much as f theproductlof the action of thels'parks is increased, so that when once. the circuit .is. adjusted it regulates itself over a wide, rangev of current. In

alternating current generator the field as which isexcited by an auxiliary directcur- 1 rent generator 6. The brushes of the dynanio b are shown connected by wires 1 and 2 with the terminals of the primary coil of the This the treatment of -flour.

transformer 0 respectively. The secondarycircuit of the transformer is shown from terminal 3 through wire 4 to the first of the electrodes m, and through all the electrodes in series, then through wire 5 to one terminal of the ozonizer. The other terminal of the ozonizer is connected through wire 6 to the other secondary terminal 7 of the transformer.

Although I have shown a particular form of apparatus for practicing this invention other forms may be used with great advantage,,butas'already stated the best results are. obtained if as described above, the air is first passed through the ozonizer and then through the sparking apparatus as here shown. It must be added that there is a suitable velocity at which the air should pass illustrate the requisite proportions by refer-- ence to an apparatus actually now in use for In this-apparatus the ozonizer is of the form and capacity known in the market as an Andreoli ozonizer of square feet capacity, the spar-king apparatus has six carbon electrodes with spark I gaps about 3 /3-2nds of an inch. The transformer is of the type known as a step-up resin oiltransformer, the voltage available on the primary circuit having about volts and that obtained on the secondary circuit being from 6000-8000 volts. This gives a potential difference between the terminals of the ozonizer of about 30004000 volts, the remainder of the potential being distributed over the spark gaps. The electric current passing through t e apparatus is of ,very small amperage being in the case above mentioned about 0.07-0.08 ampere. these conditions the best velocity of the air in the electrode chamber is aboutfifty miles per hour, and in all cases should besufiicient to avoid complete decom osition of th'e oz one and the quantity to suit t e above conditions and to treat about 10 sacks of 280 lbs. each of flour per hour' (such flour bein contained in a chamber wherein it is suitab y tossed or stirred) is 200-300 cubic feet er minute, the area of the cross section 0 the electrode chamber being about nine square inches.

To obtain thebest results from myimproved process,- it has been found that, regardless of all other conditions, such as the size of the apparatus, stren th of current,

I 3 f-numberof electrodes or 'sizeo the spark gap, 1 the dynamo?) is shown as gan the temperature within the sparking conduit.

-or chamber should be maintained at or below apoint which will prevent the complete decomposition of the ozone. Ozone can neither exist or be formed at a temperature above 350 centigrade, for if raised to a temperature above this point, it has a tendency to split up into its oxygen atoms and form 'oxids of nitrogen. It is the object of'thiscertain other constituents, the nature of which is at present unknown. When the ozonized air is subjected to the electric sparking discharge for the purpose of decomposing a portion, of the ozone by electrical action, the heat generated by the sparkingdischarges will ordinarily be sufiicient to decompose .such ozone as is not decomposed by the electrical action, hence, -I find it imperative to maintain the temperature of the gas subjected to the electric sparking discharges at or below the temperature at which ozone is decomposed, in order that the product of the process may contain ozone and oxids of nitrog Having thus described the nature of this invention and the best means I know of carrying the same into practical effect, I claim 1. A process of producing a bleaching, conditioning or sterilizing agent, which consists in first ozonizing air, and then subjecting it to the action of sparking electrical discharges at a velocity sufficiently high to prevent the complete decomposition of the ozone, sub- ,stantially as described.

2. The process of producing a bleaching, conditioning or sterilizing agent, which consists in passing air successively through an ozonizer and a spark discharge apparatus connected electrically in series, producing therebya mixture of ozone and oxids of nitrogen; substantially as described.

3. The process of producing a-bleaching, conditioning or sterilizing agent, which consists in passing air first through an ozonizer and then at a velocity sufiicient to avoid completedecomposition of the ozone through a chamber wherein it is subjected to the action of a sparking electrical discharge; sub- 'stantially as described. i

4. The process of producing a bleaching, conditioning or sterllizlng agent, which consists in passing air first through an ozonizer and then at a velocity of not less than 50' miles per hour through a chamber wherein it is subjected to the action of a sparking electrical discharge.

5. A. process ofbleaching, conditioning or sterilizing by first ozonizing air, then subjecting it to the action of sparking electrical discharges and at a velocity suliiciently high to prevent complete decomposition of ozone,

and finally bringing it into intimate contact with the material to be bleached, sterilized or conditioned.

6. The herein described'method of producing a bleaching, sterilizing or conditioning agent, which consists in subjecting air OZOIIG.

7. The herein described method of producing a bleaching, sterilizing and conditioning agent, which consists in first subjecting air to dark electrical discharges, and then subjecting it to sparking electrical discharges, said air being maintained in a condition to prevent complete decomposition of ozone.

8. The herein described method of producing a bleaching, sterilizing and conditioningagent, which consists in subjecting air successively to the action of dark and spark ing electrical discharges, the air being maintamed below a temperature at which ozone is decomposed.

9. The herein described method of. producing a bleaching, sterilizing and conditioning agent, which consists in first subjecting air to the action of dark electrical-discharges, and then subjecting it to the action of sparking electrical discharges, the air being maintamed below a temperature at which ozone is decomposed.

. 10. The herein described method of treating air for producing a bleaching, sterilizing or conditioning agent, which consists in first subjecting air to the action of dark electrical discharges, and then subjectin the air to sparking electrical discharges, the air being maintained at a velocity to prevent complete decomposition of ozone.

11. The herein described method of treating air for producing a bleaching, sterilizing or conditioning agent, which consists in first subjecting air to the action of dark electrical discharges, and then subjectin it to the action of sparking electrical discharges, said air being maintained at a temperature and at .a velocity to prevent complete decomposition of ozone.

12. In the treatment 'of ozonized air to produce a bleaching, sterilizing or conditioning agent, the step of treating the gas to produce oxide of nitrogen and maintaining the gas in a condition to prevent the entire decomposition of the ozone, substantially as 7 described.

13. In the treatment of ozonized air to produce a bleaching, sterilizing or conditioning agent, the step of treating the gas to produce oXids of nitrogen and maintaining the gas below a temperature at which ozone is entirely decomposed, substantially as described.

14. In the treatment of ozonized air to produce a bleaching, sterilizing or conditioning agent, the step of treating the gas to produce oXids of nitro en and maintaining the gas at a velocity big enough to prevent the .entire decomposition of ozone, substantially as described.

IIO

& 854,508

15. In the treatment of ozonized air to In testimony whereof I have signed my produce a bleaching,.sterilizing or conditionname to this specification in the presence of 10 Eng agenti thifa step of treatilng the gas to prlotwo subscribing Witnesses.

uce o'Xi s 0 nitro 'en an maintainin t e v i 5 gas below a, temperature at which ozoni de- SIDNEY LEETHAM composes and at a velocity high enough to Vitnesses: prevent the entire decomposition of the E. GEO; P. BOUSFIELD, ozone, substantially as described. H. BEOKETT. 

